Vending machines are provided with shelves whose size correspond gennerally to the size of the product to be dispensed. If a machine is to be used for dispensing small bar-like products such as gum, candy bars and the like, the shelves are narrow. If the machine is designed to dispense wide bagged products such as potato chips and the like, the shelves are substantially wider than those used for bar-like products. There is a need for a vending machine which is selectively adjustable so as to handle narrow or wide products at the selection of the owner of the machine. The present invention is directed to a solution of that problem.